There are known methods of delivering to the ocean bottom and raising to the surface of stations for deep-water researches, comprising lowering a ballast weight or an anchor to the ocean bottom with the use of a rope. Attached to the upper portion of the rope is a surface or subsurface float, and suspended from the same rope are recording instruments accommodated in high-strength packages. As a rule, the instrument packages being mounted on the ocean bottom land simultaneously with the ballast weight at a speed of about 2 m/s, which inevitably results in a comparatively strong impact of the instrument packages against the ocean bottom often causing damage to the instruments. The preset program completed, the carrier craft searches the bottom station with the help of a radio beacon installed on the surface float or, if the subsurface float is employed, with the help of a sonar beacon secured to the rope in close proximity to the subsurface float, usually at a depth of 100 to 150 m. After detecting the subsurface float of the station, a command is supplied through a hydroacoustic channel to an underwater hydroacoustic rope release mechanism arranged at the ballast weight, a tool thereof severs the rope in the place where it is installed, and the float due to positive buoyancy emerges to the surface of the ocean to be retrieved by the carrier craft. In all cases of delivering the recording instruments to the ocean bottom considered herein, the use is made of a winch to pay out and reel in many kilometers of the rope (cf., e.g., Walden R. G. Oceanographic and Meteorological Buoys.--Underwater Science and Technology Journal, September, 1970).
Drawbacks of the foregoing methods of implanting and recovering deep-water stations are the low productivity and insufficient reliability in operation of tethered systems with too much time spent to pay out and reel in many kilometers of the rope which may break even due to inconsiderable excessive strain, fouling, kinks, etc., which is inconsistent with the research vessel's high daily at-sea cost. As the floats or carrier craft drift continuously bringing about a continuous displacement of the rope carrying the instruments in the water mass, the quality of recording various parameters is not high. Altogether the buoy bottom stations having surface or subsurface floats, which are lowered to the ocean bottom by means of a rope directly from a carrier craft, as far as their main service performances are concerned, are inferior to the self-contained free-falling devices.
There is also known a method of delivering to the ocean bottom and raising to the surface of deep-water research stations, which comprises free submergence of the station having instrument packages in the water mass under the action of negative buoyancy of a ballast weight, landing of the station to the bottom, dropping of the ballast weight upon performance of the bottom researches and free emergence of the station under the action of positive buoyancy of a float.
There is known the design of a station for deep-water researches delivered to the ocean bottom and recovered to the surface using the method described above. The station comprises a float module and a ballast weight connected therewith by a flexible link, a flexible link release controlled through a hydroacoustic channel, and instrument packages, in this particular case--a bottom sampler in combination with the ballast weight.
The float module is provided with a system to assist locating the surfaced station. To assist in locating the submerged station, it has a sonar beacon. After being launched from a carrier craft the known self-contained sampler freely submerges at a speed of about 2 m/s. When the sampler strikes the ocean bottom its working member takes a sample of sediments, drops the ballast weight and the sampler acted upon by positive buoyancy of the float module emerges at a speed of 1.4 to 1.6 m/s to the surface of the ocean to be detected and taken aboard (cf. e.g., U.S. Pat. No. 3,572,129, cl. 73-864.31, dated Mar. 23, 1971, a prototype of the present alleged invention).
However, the foregoing method and station delivered to the bottom and recovered to the surface of the ocean using said method are characterized by a low operating reliability and frequent damages to the instruments at impacts against the ocean bottom. A ten-twelve time decrease in a speed of free submergence to 0.2-0.15 m/s ensures a soft landing of the station, but in such a case a cycle of free submergence of the station to a depth of 5000 to 6000 m will take from 20 to 30 hours, which will result in failure to exactly position the station at the predetermined area of the ocean bottom due to drifting of the station under the action of deep currents. The use of a system of near-to-bottom braking of the instruments with the ballast weight going ahead is also not efficient enough, as it may impede a close contact between the instrument packages and the ocean bottom and not ensure their soft landing at a predetermined distance from the ballast weight, an impact of the instrument packages against the leading ballast weight being not excluded.